Protecting different pages for different users

I bought the User Registration Solution Pack to perform the follwing simple task:

1. Protect pages from public access2. Assigning access rights according to users for a specific page3. After login in the user gets redirected to a specific page according to his access rights

The users should be predefined by the admin. The users should not register themselves in the system.

I have read "Restricting access to your pages using the User Registration Solution Pack", but this document is only talking about restricting a page for all users. How do I have to modify the code to restrict a page for specific users?